Unknown Error when creating or restoring bak file

[BShelf42]

Device: Samsung Galaxy 9 Note OS: Android 10 Issues: When attempting to create or restore .bak file to or from internal memory it gives "Unknown Error"

I just got a new phone with Android 10. My old phone had Android 8 and the back up and restore function works just fine with the newest app so it might be something todo with the OS update. I tested by copying the .bak file from old phone to new then back to old phone and it restore fine so I don't think it the back up itself